This is the sixth in a series of Bears position breakdowns by the Chicago Football staff leading up to the start of training camp July 25 in Bourbonnais. For more Bears and NFL coverage, visit ChicagoFootball.com.

Today: Defensive ends

Overview: The Bears were so unhappy with their defensive end play in 2013 that they’ve replaced almost everybody. Three of the top four ends on the roster coming out of training camp last year are gone, with Julius Peppers in Green Bay, Corey Wootton in Minnesota and Cheta Ozougwu waived.

The fourth, Shea McClellin, has been moved back to his college position at linebacker.

Only David Bass and Cornelius Washington return to compete at end, and both may be long shots to make the club.

The Bears committed $30.5 million guaranteed to sign Lamarr Houston away from the Oakland Raiders and Jared Allen from the Vikings, and another $9 million to ply Willie Young out of Detroit.

They will certainly replace Peppers, Wootton and McClellin as this year’s big three.

Two more free agents, Trevor Scott and Austen Lane, will compete with Bass, Washington and undrafted rookie free agent Jamil Merrel out of Rutgers for one or possibly two more roster spots as backups.

The centerpiece of this group is Allen, who could be headed for Canton some day.

All that’s missing from his résumé is a Super Bowl ring, and he spurned a strong pitch from the Seahawks to come to the Bears.

He has had 11 or more sacks in seven straight seasons.

Houston is billed as the best run-stuffing end in the league, a must-have for the Bears after finishing dead last in the NFL last season against the run, but his pass-rushing skills were lacking his first four years in the league, all of them spent in Oakland.

Don’t be surprised if Houston spends as much or more time at the three-technique as he does at end, in part because it may best fit his skill set, and in part because general manager Phil Emery has said he wants Houston, Allen and Young all on the field at the same time, and neither Allen nor Young will be playing any tackle.

Position battles: There will be no real battles to watch here as far as playing time goes. Allen will be on the field as close to 60 minutes as he can and still be effective, all the time in obvious passing situations.

Houston will log serious playing time as well, although more of it may be at tackle than end. Expect Houston outside in suspected running situations (there are no more obvious ones in the NFL any more) and short yardage, and inside the rest of the time.

Young will be on the field most of the time that Houston is inside at tackle and will give Allen an occasional breather.

The battles here are for the backup spots. Bass flashed occasionally last year and may have the slightest of edges over the rest of the group with no real leader in the clubhouse going to Bourbonnais.

Contract situations: With Allen, Houston and Young all holding freshly signed paper, there are no contract situations to speak of. Houston is guaranteed the biggest number, but his deal is not a cap-strangler.

Keep an eye on: Young is a player the Bears believe is ready to explode and become a double-digit sack guy, but his $9 million price tag for three years wouldn’t have been that hard for the Lions to match if they thought after four years of coaching him he had another step up in him.

Washington is as impressive a physical specimen as you’ll find in a locker room, but he was a chronic underachiever at Georgia and to date has looked like an athlete who’s not real sure how to play football. But new defensive line coach Paul Pasqualoni is a crusty veteran who knows how to teach the position and could turn out to be just what the doctor ordered for the Bears’ sixth-round pick last year.